Yawn

Yawn
A yawning koala
OrganismsVertebrates
Biological systemNervous system
HealthUnaffected or beneficial
ActionInvoluntary
Stimuli
MethodComplete extension of jaw, inhalation, eyes close, stretching of the eardrum, exhalation
DurationUsually 6 seconds[1]

A yawn is a reflex in vertebrate animals characterized by a long inspiratory phase with gradual mouth gaping, followed by a brief climax (or acme) with muscle stretching, and a rapid expiratory phase with muscle relaxation, which typically lasts a few seconds.[2][3] For fish and birds, this is described as gradual mouth gaping, staying open for at least 3 seconds and subsequently a rapid closure of the mouth.[4] Almost all vertebrate animals, including mammals, birds, reptiles, amphibians, and even fish, experience yawning. The study of yawning is called chasmology.[5][6][7]

Yawning (oscitation) most often occurs in adults immediately before and after sleep, during tedious activities and as a result of its contagious quality.[8] It is commonly associated with tiredness, stress, sleepiness, boredom, or even hunger. In humans, yawning is often triggered by the perception that others are yawning (for example, seeing a person yawning, or talking to someone on the phone who is yawning). This is a typical example of echopraxia and positive feedback.[9][10] This "contagious" yawning has also been observed in chimpanzees, dogs, cats, birds, and reptiles and can occur between members of different species.[11][12][13] Approximately twenty psychological reasons for yawning have been proposed by scholars but there is little agreement on the primacy of any one.[8]

During a yawn, muscles around the airway are fully stretched, including chewing and swallowing muscles.[14] Due to these strong repositioning muscle movements, the airway (lungs and throat) dilates to three or four times its original size.[15][16] The tensor tympani muscle in the middle ear contracts, which creates a rumbling noise perceived as coming from within the head; however, the noise is due to mechanical disturbance of the hearing apparatus and is not generated by the motion of air. Yawning is sometimes accompanied, in humans and other animals, by an instinctive act of stretching several parts of the body including the arms, neck, shoulders and back.

  1. ^ Underwood, Emily (4 October 2016). "The bigger your brain, the longer you yawn". Science. doi:10.1126/science.aah7379.
  2. ^ Barbizet, J (1958). "Yawning". J Neurol Neurosurg Psychiatry. 21 (3): 203–209. doi:10.1136/jnnp.21.3.203. PMC 497319. PMID 13576171.
  3. ^ Provine, RR (1986). "Yawning as a stereotyped action pattern and releasing stimulus". Ethology. 72 (2): 109–122. Bibcode:1986Ethol..72..109P. doi:10.1111/j.1439-0310.1986.tb00611.x.
  4. ^ Baenninger, R (1987). "Some comparative aspects of yawning in Betta splendens, Homo sapiens, Panthera leo, and Papio sphinx". J Comp Psychol. 101 (4): 349. doi:10.1037/0735-7036.101.4.349.
  5. ^ Seuntjens, Wolter (2010). "The Hidden Sexuality of the Yawn and the Future of Chasmology". The Mystery of Yawning in Physiology and Disease. Frontiers of Neurology and Neuroscience. Vol. 28. pp. 55–62. doi:10.1159/000307081. ISBN 978-3-8055-9404-2. PMID 20357463.
  6. ^ Mikami, Akichika (January 2011). "Olivier Walusinski (Ed.): The Mystery of Yawning in Physiology and Disease: Karger, Basel, 2010, 160 pp". Primates. 52 (1): 97–99. doi:10.1007/s10329-010-0222-6. S2CID 16749981.
  7. ^ Teive, Hélio A. G.; Munhoz, Renato P.; Camargo, Carlos Henrique F.; Walusinski, Olivier (July 2018). "Yawning in neurology: a review". Arquivos de Neuro-Psiquiatria. 76 (7): 473–480. doi:10.1590/0004-282X20180057. PMID 30066799. S2CID 51890021.
  8. ^ a b Anderson, James R.; Meno, Pauline (2003). "Psychological Influences on Yawning in Children". Current Psychology Letters. 2 (11). Archived from the original on 2013-05-29. Retrieved 2012-05-15.
  9. ^ Camazine, Deneubourg, Franks, Sneyd, Theraulaz, Bonabeau, Self-Organization in Biological Systems, Princeton University Press, 2003. ISBN 0-691-11624-5, ISBN 0-691-01211-3 (pbk.) p. 18.
  10. ^ Brown, Beverley J.; Kim, Soyoung; Saunders, Hannah; Bachmann, Clarissa; Thompson, Jessica; Ropar, Danielle; Jackson, Stephen R.; Jackson, Georgina M. (2017). "A Neural Basis for Contagious Yawning". Current Biology. 27 (17): 2713–2717.e2. Bibcode:2017CBio...27E2713B. doi:10.1016/j.cub.2017.07.062. PMID 28867202.
  11. ^ Shepherd, Alex J.; Senju, Atsushi; Joly-Mascheroni, Ramiro M. (2008). "Dogs catch human yawns". Biology Letters. 4 (5): 446–8. doi:10.1098/rsbl.2008.0333. PMC 2610100. PMID 18682357.
  12. ^ Madsen, Elanie E.; Persson, Tomas; Sayehli, Susan; Lenninger, Sara; Sonesson, Göran (October 16, 2013). "Chimpanzees Show a Developmental Increase in Susceptibility to Contagious Yawning: A Test of the Effect of Ontogeny and Emotional Closeness on Yawn Contagion". PLOS ONE. 8 (10): e76266. Bibcode:2013PLoSO...876266M. doi:10.1371/journal.pone.0076266. PMC 3797813. PMID 24146848.
  13. ^ "Chimps find human yawn contagious, but is it monkey see, monkey do?". Los Angeles Times. October 16, 2013.
  14. ^ Cite error: The named reference :4 was invoked but never defined (see the help page).
  15. ^ Baenninger, R. (1997-06-01). "On yawning and its functions". Psychonomic Bulletin & Review. 4 (2): 198–207. doi:10.3758/BF03209394. PMID 21331826. S2CID 18001020.
  16. ^ Barbizet, J. (1958-08-01). "Yawning". Journal of Neurology, Neurosurgery, and Psychiatry. 21 (3): 203–209. doi:10.1136/jnnp.21.3.203. PMC 497319. PMID 13576171.